Why America's Nuclear Submarine Fleet Has No Equal

The Block IV Virginia-class submarines—the first of which are currently in the initial stages of construction—focus on reliability and maintenance improvements, Jabaley said. Indeed, because they will require far less time in dry dock, the boats will be available for extra deployments (an SSN normally deploys 14 times during its 33-year lifespan)—which will help the Navy with its mission to maintain a global submarine presence. “Once you wrap all of those changes into the ship’s maintenance plan, it allowed us, starting with the Block IV submarines, to reduce four depot level maintenance periods down to three and increase the deployments from 14 to up to 15,” Jabaley said.

However, the biggest improvement to the Virginia-class will come with the Block V vessels—the first of which will start construction in 2019 as the second submarine (SSN-803) built that year. The Block V submarines will add a Virginia Payload Module (VPM) that will add four additional payload tubes amidship, each of which can accommodate seven Tomahawk cruise missiles for a total of 28 weapons. Overall, the Block V Virginia-class will be capable of launching 40 Tomahawk cruise missiles from its payload tubes.

The United States Navy might defer developing a new next-generation SSN(X) unless such a design holds the potential to provide a revolutionary leap over a modernized variant of the current Virginia-class attack submarine (SSN).

While the Virginia-class was developed in the 1990s to be a cheaper alternative to the much more capable and expensive Seawolf-class (SSN-21-class), the SSN-774-class was designed to be as stealthy and to have greater multi-mission capabilities than its larger counterpart. Over the years, the Virginia-class has proven to be an adaptable and versatile design with plenty of room for growth. Indeed, the Virginia-class submarine—or VCS as many senior U.S. Navy officials call it—may prove so capable that a futureSSN(X)—which is tentatively planned for 2034—might prove to be unnecessary.

“When is the transition from Virginia-class submarine to SSN(X)? And it’s currently scheduled for about 2034.” Naval Sea Systems Command’s program executive officer for submarines Rear Adm. Michael Jabaley toldThe National Interest during a Sept. 16 interview in his office. “So we have Blocks V, VI and VII on the Virginia and at some point in the future, we’ll have to sit down and make that decision. And the decision will be: Ok, has our science and technology and research and development work to date shown there is enough there to warrant designing a new submarine and starting to built it at that point or should we move that point—most probably out to the right—and keep building Virginia because with Block VIII we can insert the most promising technologies and make it still be the best submarine out there and perhaps wait for some phenomenal technological development to come to fruition.”

The Navy will have to make the decision on developing a new SSN(X) with potentially game-changing technologies or continue building advanced Virginia-class variants roughly seven or eight years from now, Jabaley said. Though Jabaley didn’t address what kinds of “phenomenal technological developments” it might take to justify developing a future SSN(X), during his earlier testimony before the House Armed Services Committee (HASC) in July, he suggested that a future SSN might act as an underwater mothership for unmanned underwater vehicles.

Moreover, in order to drastically improve acoustical performance, a next-generation submarine would need to dispense with moving parts. “At some point we’re going to have to move beyond a rotating mechanical device to push the ship through the water,” Jabaleytold the HASC. “Although we’re not there yet on the oceans being transparent, one of the biggest things that causes noise to be radiated into the water is the rotating machinery and the propulsor itself moving through the water and exciting various parts of the stern and the submarine to radiate noise.”

The Navy has essentially reached the limits of what is possible for acoustic signature reduction with a purely mechanical system. While the future Ohio Replacement Program ballistic missile submarines (SSBN) are expected to use a permanent magnetic motor to increase stealth, Jabaley wants to take a step further. “The field of biomimetics is very interesting to me when you look at nature in action and you think: ‘Boy, it would be great if we could design something that would take that leap forward and get us into a realm that would be acoustic-self unlike anything we’ve ever done before,’” Jabaley said told the Congress.